diff --git a/packages/twenty-sdk/package.json b/packages/twenty-sdk/package.json
index d6e9653870c..fc705f45902 100644
--- a/packages/twenty-sdk/package.json
+++ b/packages/twenty-sdk/package.json
@@ -32,6 +32,11 @@
       "import": "./dist/define/index.mjs",
       "require": "./dist/define/index.cjs"
     },
+    "./define-runtime-stub": {
+      "types": "./dist/define/index.d.ts",
+      "import": "./dist/define-runtime-stub/index.mjs",
+      "require": "./dist/define-runtime-stub/index.cjs"
+    },
     "./front-component": {
       "types": "./dist/front-component/index.d.ts",
       "import": "./dist/front-component/index.mjs",
@@ -108,6 +113,9 @@
       "define": [
         "dist/define/index.d.ts"
       ],
+      "define-runtime-stub": [
+        "dist/define/index.d.ts"
+      ],
       "front-component": [
         "dist/front-component/index.d.ts"
       ],
diff --git a/packages/twenty-sdk/project.json b/packages/twenty-sdk/project.json
index 4fa38db83f4..164a37df604 100644
--- a/packages/twenty-sdk/project.json
+++ b/packages/twenty-sdk/project.json
@@ -14,7 +14,7 @@
       "options": {
         "cwd": "{projectRoot}",
         "commands": [
-          "npx rimraf dist && npx vite build -c vite.config.node.ts && npx vite build -c vite.config.define.ts && npx vite build -c vite.config.billing.ts && npx vite build -c vite.config.front-component.ts && npx vite build -c vite.config.browser.ts",
+          "npx rimraf dist && npx vite build -c vite.config.node.ts && npx vite build -c vite.config.define.ts && npx vite build -c vite.config.define-stub.ts && npx vite build -c vite.config.billing.ts && npx vite build -c vite.config.front-component.ts && npx vite build -c vite.config.browser.ts",
           "tsgo -p tsconfig.lib.json --declaration --emitDeclarationOnly --noEmit false --outDir dist --rootDir src && npx tsc-alias -p tsconfig.lib.json --outDir dist",
           "npx rimraf 'dist/sdk' 'dist/define/**/*.d.ts' 'dist/define/**/*.d.ts.map' 'dist/billing/**/*.d.ts' 'dist/billing/**/*.d.ts.map' 'dist/front-component/**/*.d.ts' 'dist/front-component/**/*.d.ts.map' && npx rollup -c rollup.config.sdk-dts.mjs"
         ],
@@ -26,7 +26,7 @@
       "dependsOn": ["^build"],
       "options": {
         "cwd": "packages/twenty-sdk",
-        "command": "npx rimraf dist && npx vite build -c vite.config.node.ts && npx vite build -c vite.config.define.ts && npx vite build -c vite.config.billing.ts && npx vite build -c vite.config.front-component.ts && npx vite build -c vite.config.browser.ts && tsgo -p tsconfig.lib.json --declaration --emitDeclarationOnly --noEmit false --outDir dist --rootDir src && npx tsc-alias -p tsconfig.lib.json --outDir dist && npx rimraf 'dist/sdk' 'dist/define/**/*.d.ts' 'dist/define/**/*.d.ts.map' 'dist/billing/**/*.d.ts' 'dist/billing/**/*.d.ts.map' 'dist/front-component/**/*.d.ts' 'dist/front-component/**/*.d.ts.map' && npx rollup -c rollup.config.sdk-dts.mjs && npx vite build -c vite.config.node.ts --watch & npx vite build -c vite.config.define.ts --watch & npx vite build -c vite.config.billing.ts --watch & npx vite build -c vite.config.front-component.ts --watch & npx vite build -c vite.config.browser.ts --watch"
+        "command": "npx rimraf dist && npx vite build -c vite.config.node.ts && npx vite build -c vite.config.define.ts && npx vite build -c vite.config.define-stub.ts && npx vite build -c vite.config.billing.ts && npx vite build -c vite.config.front-component.ts && npx vite build -c vite.config.browser.ts && tsgo -p tsconfig.lib.json --declaration --emitDeclarationOnly --noEmit false --outDir dist --rootDir src && npx tsc-alias -p tsconfig.lib.json --outDir dist && npx rimraf 'dist/sdk' 'dist/define/**/*.d.ts' 'dist/define/**/*.d.ts.map' 'dist/billing/**/*.d.ts' 'dist/billing/**/*.d.ts.map' 'dist/front-component/**/*.d.ts' 'dist/front-component/**/*.d.ts.map' && npx rollup -c rollup.config.sdk-dts.mjs && npx vite build -c vite.config.node.ts --watch & npx vite build -c vite.config.define.ts --watch & npx vite build -c vite.config.billing.ts --watch & npx vite build -c vite.config.front-component.ts --watch & npx vite build -c vite.config.browser.ts --watch"
       }
     },
     "start": {
@@ -93,11 +93,12 @@
       "inputs": ["{projectRoot}/src/sdk/**/*"],
       "outputs": [
         "{projectRoot}/dist/define",
+        "{projectRoot}/dist/define-runtime-stub",
         "{projectRoot}/dist/front-component"
       ],
       "options": {
         "cwd": "{projectRoot}",
-        "command": "npx vite build -c vite.config.define.ts && npx vite build -c vite.config.front-component.ts && npx rollup -c rollup.config.sdk-dts.mjs"
+        "command": "npx vite build -c vite.config.define.ts && npx vite build -c vite.config.define-stub.ts && npx vite build -c vite.config.front-component.ts && npx rollup -c rollup.config.sdk-dts.mjs"
       }
     }
   }
diff --git a/packages/twenty-sdk/src/cli/utilities/build/common/app-build-alias.ts b/packages/twenty-sdk/src/cli/utilities/build/common/app-build-alias.ts
new file mode 100644
index 00000000000..e31f7f6c531
--- /dev/null
+++ b/packages/twenty-sdk/src/cli/utilities/build/common/app-build-alias.ts
@@ -0,0 +1,14 @@
+/**
+ * esbuild aliases applied when building user app code (logic functions
+ * and front components).
+ *
+ * `twenty-sdk/define` is an authoring surface whose `defineXxx` helpers
+ * only run build-time validation. Its compiled `dist` also transitively
+ * imports `zod` (+ every locale) and `@sniptt/guards`. Redirecting to
+ * `twenty-sdk/define-runtime-stub` — which exposes passthrough identity
+ * versions of the same surface — lets esbuild tree-shake the zod/sniptt
+ * dependencies out of user bundles.
+ */
+export const APP_BUILD_ALIASES: Record<string, string> = {
+  'twenty-sdk/define': 'twenty-sdk/define-runtime-stub',
+};
diff --git a/packages/twenty-sdk/src/cli/utilities/build/common/build-application.ts b/packages/twenty-sdk/src/cli/utilities/build/common/build-application.ts
index 5b453c6d99e..82274ae6c4a 100644
--- a/packages/twenty-sdk/src/cli/utilities/build/common/build-application.ts
+++ b/packages/twenty-sdk/src/cli/utilities/build/common/build-application.ts
@@ -8,6 +8,7 @@ import {
 } from 'twenty-shared/application';
 import { FileFolder } from 'twenty-shared/types';
 
+import { APP_BUILD_ALIASES } from '@/cli/utilities/build/common/app-build-alias';
 import { esbuildOneShotBuild } from '@/cli/utilities/build/common/esbuild-one-shot-build';
 import { LOGIC_FUNCTION_EXTERNAL_MODULES } from '@/cli/utilities/build/common/esbuild-watcher';
 import { getBaseFrontComponentBuildOptions } from '@/cli/utilities/build/common/front-component-build/utils/get-base-front-component-build-options';
@@ -73,6 +74,7 @@ export const buildApplication = async (
       platform: 'node',
       outdir: join(options.appPath, OUTPUT_DIR),
       outExtension: { '.js': '.mjs' },
+      alias: APP_BUILD_ALIASES,
       external: LOGIC_FUNCTION_EXTERNAL_MODULES,
       tsconfig: join(options.appPath, 'tsconfig.json'),
       sourcemap: true,
@@ -95,6 +97,7 @@ export const buildApplication = async (
       sourcemap: true,
       metafile: true,
       logLevel: 'silent',
+      alias: APP_BUILD_ALIASES,
       plugins: [...getFrontComponentBuildPlugins()],
     },
     onFileBuilt: collectFileBuilt,
diff --git a/packages/twenty-sdk/src/cli/utilities/build/common/esbuild-watcher.ts b/packages/twenty-sdk/src/cli/utilities/build/common/esbuild-watcher.ts
index 32831c8d3f4..f7f7bc7f5bf 100644
--- a/packages/twenty-sdk/src/cli/utilities/build/common/esbuild-watcher.ts
+++ b/packages/twenty-sdk/src/cli/utilities/build/common/esbuild-watcher.ts
@@ -1,3 +1,4 @@
+import { APP_BUILD_ALIASES } from '@/cli/utilities/build/common/app-build-alias';
 import { cleanupRemovedFiles } from '@/cli/utilities/build/common/cleanup-removed-files';
 import { processEsbuildResult } from '@/cli/utilities/build/common/esbuild-result-processor';
 import { FRONT_COMPONENT_EXTERNAL_MODULES } from '@/cli/utilities/build/common/front-component-build/constants/front-component-external-modules';
@@ -163,6 +164,7 @@ export class EsbuildWatcher implements RestartableWatcher {
       platform: this.config.platform,
       outdir: outputDir,
       outExtension: { '.js': '.mjs' },
+      alias: APP_BUILD_ALIASES,
       external: this.config.externalModules,
       tsconfig: path.join(this.appPath, 'tsconfig.json'),
       jsx: this.config.jsx,
diff --git a/packages/twenty-sdk/src/sdk/define/runtime-stub.ts b/packages/twenty-sdk/src/sdk/define/runtime-stub.ts
new file mode 100644
index 00000000000..f5002b9354d
--- /dev/null
+++ b/packages/twenty-sdk/src/sdk/define/runtime-stub.ts
@@ -0,0 +1,259 @@
+/**
+ * Runtime stub for `twenty-sdk/define`.
+ *
+ * `twenty-sdk/define` is an authoring API: its `defineXxx` helpers only run
+ * build-time validation, and the full module transitively pulls in `zod`
+ * (including every locale) plus `@sniptt/guards`. In a built logic function
+ * or front component that only needs `default.config.handler` /
+ * `default.config.component` at runtime, those extras inflate bundles by
+ * ~1MB per file.
+ *
+ * The CLI aliases `twenty-sdk/define` to this stub when bundling user code,
+ * so the published SDK continues to do build-time validation while user
+ * bundles ship only the identity passthroughs and the handful of enum
+ * constants they actually reference. Tree-shaking removes the rest.
+ *
+ * Keep this file free of imports that transitively reach `zod` — i.e. do not
+ * re-export from the `twenty-shared/types` barrel, which pulls
+ * `richTextValueSchema` (zod) in along for the ride.
+ */
+
+export { STANDARD_OBJECTS as STANDARD_OBJECT } from 'twenty-shared/metadata';
+export { STANDARD_OBJECTS as STANDARD_OBJECT_UNIVERSAL_IDENTIFIERS } from 'twenty-shared/metadata';
+
+export { generateDefaultFieldUniversalIdentifier } from '@/sdk/define/objects/generate-default-field-universal-identifier';
+export { getPublicAssetUrl } from '@/sdk/define/get-public-asset-url';
+
+type PassthroughResult<T> = {
+  success: true;
+  config: T;
+  errors: readonly never[];
+};
+
+const passthrough = <T>(config: T): PassthroughResult<T> => ({
+  success: true,
+  config,
+  errors: [],
+});
+
+export const defineAgent = passthrough;
+export const defineApplication = passthrough;
+export const defineField = passthrough;
+export const defineFrontComponent = passthrough;
+export const defineLogicFunction = passthrough;
+export const defineNavigationMenuItem = passthrough;
+export const defineObject = passthrough;
+export const definePageLayout = passthrough;
+export const definePageLayoutTab = passthrough;
+export const definePostInstallLogicFunction = passthrough;
+export const definePreInstallLogicFunction = passthrough;
+export const defineRole = passthrough;
+export const defineSkill = passthrough;
+export const defineView = passthrough;
+
+export const createValidationResult = <T>({
+  config,
+  errors = [],
+}: {
+  config: T;
+  errors?: string[];
+}) => ({
+  success: errors.length === 0,
+  config,
+  errors,
+});
+
+export const validateFields = (): string[] => [];
+
+// ─── Enum constants ─────────────────────────────────────────────────────────
+// Values inlined (rather than re-exported from `twenty-shared/types`) to keep
+// this stub free of the zod-using `richTextValueSchema` re-export that lives
+// in the same barrel.
+
+export const AggregateOperations = {
+  MIN: 'MIN',
+  MAX: 'MAX',
+  AVG: 'AVG',
+  SUM: 'SUM',
+  COUNT: 'COUNT',
+  COUNT_UNIQUE_VALUES: 'COUNT_UNIQUE_VALUES',
+  COUNT_EMPTY: 'COUNT_EMPTY',
+  COUNT_NOT_EMPTY: 'COUNT_NOT_EMPTY',
+  COUNT_TRUE: 'COUNT_TRUE',
+  COUNT_FALSE: 'COUNT_FALSE',
+  PERCENTAGE_EMPTY: 'PERCENTAGE_EMPTY',
+  PERCENTAGE_NOT_EMPTY: 'PERCENTAGE_NOT_EMPTY',
+} as const;
+
+export const DateDisplayFormat = {
+  RELATIVE: 'RELATIVE',
+  USER_SETTINGS: 'USER_SETTINGS',
+  CUSTOM: 'CUSTOM',
+} as const;
+
+export const FieldMetadataSettingsOnClickAction = {
+  COPY: 'COPY',
+  OPEN_LINK: 'OPEN_LINK',
+  OPEN_IN_APP: 'OPEN_IN_APP',
+} as const;
+
+export const FieldType = {
+  ACTOR: 'ACTOR',
+  ADDRESS: 'ADDRESS',
+  ARRAY: 'ARRAY',
+  BOOLEAN: 'BOOLEAN',
+  CURRENCY: 'CURRENCY',
+  DATE: 'DATE',
+  DATE_TIME: 'DATE_TIME',
+  EMAILS: 'EMAILS',
+  FILES: 'FILES',
+  FULL_NAME: 'FULL_NAME',
+  LINKS: 'LINKS',
+  MORPH_RELATION: 'MORPH_RELATION',
+  MULTI_SELECT: 'MULTI_SELECT',
+  NUMBER: 'NUMBER',
+  NUMERIC: 'NUMERIC',
+  PHONES: 'PHONES',
+  POSITION: 'POSITION',
+  RATING: 'RATING',
+  RAW_JSON: 'RAW_JSON',
+  RELATION: 'RELATION',
+  RICH_TEXT: 'RICH_TEXT',
+  SELECT: 'SELECT',
+  TEXT: 'TEXT',
+  TS_VECTOR: 'TS_VECTOR',
+  UUID: 'UUID',
+} as const;
+
+export const HTTPMethod = {
+  GET: 'GET',
+  POST: 'POST',
+  PUT: 'PUT',
+  PATCH: 'PATCH',
+  DELETE: 'DELETE',
+} as const;
+
+export const NavigationMenuItemType = {
+  VIEW: 'VIEW',
+  FOLDER: 'FOLDER',
+  LINK: 'LINK',
+  OBJECT: 'OBJECT',
+  RECORD: 'RECORD',
+  PAGE_LAYOUT: 'PAGE_LAYOUT',
+} as const;
+
+export const NumberDataType = {
+  FLOAT: 'float',
+  INT: 'int',
+  BIGINT: 'bigint',
+} as const;
+
+export const ObjectRecordGroupByDateGranularity = {
+  DAY: 'DAY',
+  MONTH: 'MONTH',
+  QUARTER: 'QUARTER',
+  YEAR: 'YEAR',
+  WEEK: 'WEEK',
+  DAY_OF_THE_WEEK: 'DAY_OF_THE_WEEK',
+  MONTH_OF_THE_YEAR: 'MONTH_OF_THE_YEAR',
+  QUARTER_OF_THE_YEAR: 'QUARTER_OF_THE_YEAR',
+  NONE: 'NONE',
+} as const;
+
+export const OnDeleteAction = {
+  CASCADE: 'CASCADE',
+  RESTRICT: 'RESTRICT',
+  SET_NULL: 'SET_NULL',
+  NO_ACTION: 'NO_ACTION',
+} as const;
+
+export const PageLayoutTabLayoutMode = {
+  GRID: 'GRID',
+  VERTICAL_LIST: 'VERTICAL_LIST',
+  CANVAS: 'CANVAS',
+} as const;
+
+export const PermissionFlag = {
+  API_KEYS_AND_WEBHOOKS: 'API_KEYS_AND_WEBHOOKS',
+  WORKSPACE: 'WORKSPACE',
+  WORKSPACE_MEMBERS: 'WORKSPACE_MEMBERS',
+  ROLES: 'ROLES',
+  DATA_MODEL: 'DATA_MODEL',
+  SECURITY: 'SECURITY',
+  WORKFLOWS: 'WORKFLOWS',
+  IMPERSONATE: 'IMPERSONATE',
+  SSO_BYPASS: 'SSO_BYPASS',
+  APPLICATIONS: 'APPLICATIONS',
+  MARKETPLACE_APPS: 'MARKETPLACE_APPS',
+  LAYOUTS: 'LAYOUTS',
+  BILLING: 'BILLING',
+  AI_SETTINGS: 'AI_SETTINGS',
+  AI: 'AI',
+  VIEWS: 'VIEWS',
+  UPLOAD_FILE: 'UPLOAD_FILE',
+  DOWNLOAD_FILE: 'DOWNLOAD_FILE',
+  SEND_EMAIL_TOOL: 'SEND_EMAIL_TOOL',
+  HTTP_REQUEST_TOOL: 'HTTP_REQUEST_TOOL',
+  CODE_INTERPRETER_TOOL: 'CODE_INTERPRETER_TOOL',
+  IMPORT_CSV: 'IMPORT_CSV',
+  EXPORT_CSV: 'EXPORT_CSV',
+  CONNECTED_ACCOUNTS: 'CONNECTED_ACCOUNTS',
+  PROFILE_INFORMATION: 'PROFILE_INFORMATION',
+} as const;
+
+export const RelationType = {
+  MANY_TO_ONE: 'MANY_TO_ONE',
+  ONE_TO_MANY: 'ONE_TO_MANY',
+} as const;
+
+export const ViewFilterGroupLogicalOperator = {
+  AND: 'AND',
+  OR: 'OR',
+  NOT: 'NOT',
+} as const;
+
+export const ViewFilterOperand = {
+  IS: 'IS',
+  IS_NOT_NULL: 'IS_NOT_NULL',
+  IS_NOT: 'IS_NOT',
+  LESS_THAN_OR_EQUAL: 'LESS_THAN_OR_EQUAL',
+  GREATER_THAN_OR_EQUAL: 'GREATER_THAN_OR_EQUAL',
+  IS_BEFORE: 'IS_BEFORE',
+  IS_AFTER: 'IS_AFTER',
+  CONTAINS: 'CONTAINS',
+  DOES_NOT_CONTAIN: 'DOES_NOT_CONTAIN',
+  IS_EMPTY: 'IS_EMPTY',
+  IS_NOT_EMPTY: 'IS_NOT_EMPTY',
+  IS_RELATIVE: 'IS_RELATIVE',
+  IS_IN_PAST: 'IS_IN_PAST',
+  IS_IN_FUTURE: 'IS_IN_FUTURE',
+  IS_TODAY: 'IS_TODAY',
+  VECTOR_SEARCH: 'VECTOR_SEARCH',
+} as const;
+
+export const ViewKey = {
+  INDEX: 'INDEX',
+} as const;
+
+export const ViewOpenRecordIn = {
+  SIDE_PANEL: 'SIDE_PANEL',
+  RECORD_PAGE: 'RECORD_PAGE',
+} as const;
+
+export const ViewSortDirection = {
+  ASC: 'ASC',
+  DESC: 'DESC',
+} as const;
+
+export const ViewType = {
+  TABLE: 'TABLE',
+  KANBAN: 'KANBAN',
+  CALENDAR: 'CALENDAR',
+  FIELDS_WIDGET: 'FIELDS_WIDGET',
+  TABLE_WIDGET: 'TABLE_WIDGET',
+} as const;
+
+export const ViewVisibility = {
+  WORKSPACE: 'WORKSPACE',
+  UNLISTED: 'UNLISTED',
+} as const;
diff --git a/packages/twenty-sdk/tsconfig.json b/packages/twenty-sdk/tsconfig.json
index 8cce57bef3b..60952eb7439 100644
--- a/packages/twenty-sdk/tsconfig.json
+++ b/packages/twenty-sdk/tsconfig.json
@@ -26,6 +26,7 @@
     "vite.config.node.ts",
     "vite.config.browser.ts",
     "vite.config.define.ts",
+    "vite.config.define-stub.ts",
     "vite.config.front-component.ts",
     "jest.config.mjs"
   ]
diff --git a/packages/twenty-sdk/vite.config.define-stub.ts b/packages/twenty-sdk/vite.config.define-stub.ts
new file mode 100644
index 00000000000..4a7ff6eb046
--- /dev/null
+++ b/packages/twenty-sdk/vite.config.define-stub.ts
@@ -0,0 +1,65 @@
+import path from 'path';
+import { type PackageJson } from 'type-fest';
+import { defineConfig } from 'vite';
+import tsconfigPaths from 'vite-tsconfig-paths';
+
+import packageJson from './package.json';
+
+export default defineConfig(() => {
+  return {
+    root: __dirname,
+    cacheDir: '../../node_modules/.vite/packages/twenty-sdk-define-stub',
+    resolve: {
+      alias: {
+        '@/': path.resolve(__dirname, 'src') + '/',
+      },
+    },
+    plugins: [
+      tsconfigPaths({
+        root: __dirname,
+      }),
+    ],
+    build: {
+      emptyOutDir: false,
+      outDir: 'dist/define-runtime-stub',
+      sourcemap: true,
+      lib: {
+        entry: 'src/sdk/define/runtime-stub.ts',
+        name: 'twenty-sdk-define-runtime-stub',
+        formats: ['es', 'cjs'],
+        fileName: (format) => `index.${format === 'es' ? 'mjs' : 'cjs'}`,
+      },
+      rollupOptions: {
+        external: (id: string) => {
+          if (/^node:/.test(id)) {
+            return true;
+          }
+
+          const builtins = [
+            'child_process',
+            'crypto',
+            'fs',
+            'fs/promises',
+            'module',
+            'os',
+            'path',
+            'stream',
+            'url',
+            'util',
+          ];
+
+          if (builtins.includes(id)) {
+            return true;
+          }
+
+          const deps = Object.keys(
+            (packageJson as PackageJson).dependencies || {},
+          );
+
+          return deps.some((dep) => id === dep || id.startsWith(dep + '/'));
+        },
+      },
+    },
+    logLevel: 'warn' as const,
+  };
+});